Anise Swallowtail Butterflies

Anise Swallowtail Butterfly resting on child's finger

Raising anise swallowtail butterflies is one of our favorite activities and I recommend that every family does this at least once. Children can witness the magical life cycle of butterflies and learn about their vital role in pollinating plants. Helping to feed and care for the caterpillars also teaches children responsibility. You and your children will enjoy this activity and discover many new facts about these captivating insects.

What do anise swallowtail butterflies look like?

The yellow anise butterfly has a 3-inch wingspan. The primary wings are pale to bright yellow, and framed in black. The lower wings have swatches of blue within the black stripe and dots of burnt orange. Black swallowtails look similar but are mostly black with yellow stripes and blue spots and two orange dots. It’s like their colors have been reversed!

Yellow anise swallowtail butterfly
Black anise swallowtail butterfly, photo by Gardens With Wings

Where do anise swallowtail butterflies live?

Yellow Anise Swallowtail Butterflies (Papilio zelicaon) are common butterflies found on the West Coast of Northern America. We are in California and raise Yellow Anise Swallowtail caterpillars every year. They are not endangered or poisonous which makes this a safe species for home observation with young children.

If you are on the East Coast, black swallowtail butterflies (Papilio polyxenes) are more common. The caterpillars are often called parsley worms because they feed on parsley. When we lived in Manhattan, we were excited to find black swallowtail caterpillars on the rooftop garden, sadly our building pulled out all the parsley plants and consider them pests. The caterpillars are harmless and will turn into beautiful butterflies!

Anise swallowtail butterflies can be seen fluttering around rooftop gardens in Manhattan to coastal trails in California. They are very common and easy to find once you start looking.

How to find anise swallowtail caterpillars or eggs

Along the California coast, anise butterflies are common in the early spring to fall. The eggs and caterpillars can be found on host plants in your garden, on a hillside, on a trail, or even on the roadside. We are in the bay area where fennel grows like weeds so we have easily found eggs and caterpillars on walking paths in our neighborhood.

►  Watch a reel of our caterpillar eggs

Inspecting some fennel for anise butterfly eggs or caterpillars

The easiest way to find an anise swallowtail caterpillar is to look for specks of black against the bright green stems and leaves of the host plant. Young caterpillars are black which makes them easier to find. Caterpillar poop looks like tiny black balls, and if you find some it means there is a caterpillar on the plant. One thing to note is that ladybug nymphs look strikingly similar to second-instar caterpillars and they are often found on the same plant.

Anise swallowtail caterpillar compared to a ladybug nymph

How to find caterpillar eggs

Caterpillar eggs are a bit harder to find and tend to be on the top of the plant. Anise butterflies lay one egg at a time which ranges from light yellow to black in color and are perfectly spherical. Please note that other butterfly species have different colored and shaped eggs. See the lifecycle below for pictures of anise swallowtail eggs.

How to collect the caterpillars and eggs

To bring the caterpillars and eggs home, cut the stem it is on. Make sure to clip the stem long enough to keep it in water as you would with freshly cut flowers. Put these stems in the glass or vase along with more stems to feed your caterpillar. Do not try to remove the caterpillar from the stem as you might kill it.

If you are unable to find an egg or caterpillar, you can order them from a butterfly farm. Please note that caterpillars may not ship to all states.

What do anise swallowtail caterpillars eat?

Plants that caterpillars eat are called host plants. According to, yellow anise caterpillars have 23 confirmed host plants in California. However, you can feed your caterpillars fresh fennel, dill, parsley, or cilantro. I suggest growing these in your garden or purchasing pesticide-free herbs so as to not kill your caterpillars.

Common Lomatium, Lomatium Utriculatum, bladder parsnip, or Hog Fennel

Spring Gold aka Common Lomatium (native plant)

If you would like to attract yellow anise swallowtails to your yard you can plant Spring Gold plants. They are also known as Common Lomatium, Lomatium Utriculatum, bladder parsnip, or Hog Fennel. Spring Gold is native to California and can be found elsewhere along the west coast of North America. In the fall, sprinkle some seeds in the dirt as you would wildflowers. They will sprout in the spring. Spring Golds are one of the only plants native to California that are a confirmed host plant for swallowtail butterfly caterpillars and the primary source of nectar for endangered checkerspot butterflies.

I purchased seeds online from Northwest Meadowscapes and had enough to share with many neighbors.

Fennel (invasive plant)

Fennel leaves are feathery and bright green in color and have a delicate, licorice-like scent when you rub the leaves.

Since we are in California, fennel is a common host plant for anise swallowtail caterpillars. However, fennel is It is native to Southern Europe and extremely invasive in California and is spreading all the way to Texas. Do not plant fennel in your garden. It spreads like a weed. Instead, grow plants that are native to your area that are host plants for butterflies.

Safety Tip: Look for plants that you know. Fennel is easy to spot. Beware of poison hemlock that can look similar to fennel but can be mistaken for cilantro, carrot, parsnip, and many other edible plants. Spring Golds have yellow flowers. Poison Hemlock has white flowers. Generally, avoid anything that looks like poison hemlock if you don’t know for sure that it’s safe.

Parsley and Cilantro

Parsley and cilantro are easy to grow. You can also purchase these herbs from your local grocery store but make sure they are pesticide-free as they could kill your caterpillars.

Anise swallowtail butterfly lifecycle

A freshly laid anise swallowtail butterfly egg
Anise swallowtail butterfly eggs halfway through development
Anise swallowtail butterfly eggs that are about to hatch turn black


Yellow Anise butterfly eggs are perfectly round and yellow in color. Over 4-6 days, the eggs develop a purple stripe, gradually darken, then turn black right before they hatch. They look exactly like a poppy seed.

Caterpillar Stages

An anise butterfly caterpillar eating its egg case
A newly hatched caterpillar is barely bigger than the tip of a pen

First Instar

A newly hatched yellow anise caterpillar quickly turns black, and if you look with a magnifying glass you can see a thin white band around the center of its body. You may observe the caterpillar eating the egg case it came out of. This is the first instar stage. It may look like it is barely moving but it will double in size overnight. Even at this stage, you can see the little hairs, called setae.

► Watch a reel of our caterpillar eating its egg case

Newly molted second instar anise swallowtail caterpillar

Second Instar

In about 2 days the caterpillar will shed its skin for the first time. This process is called molting and allows the caterpillar to expand in size. Caterpillars will eat their skins after they emerge so you don’t always notice they molted. After the first molt, it becomes a second instar and is still black but the white stripe is more noticeable and the setae begin to look like spikes.

Second, third, and 4th instar caterpillars

Third Instar

After the third molt, some orange coloring will appear along with what looks like spikes covering the entire caterpillar. The white band now has some yellow specs.

4th instar caterpillars begin developing green coloring

Fourth Instar

After the fourth molt, the anise caterpillar becomes even more colorful as the bright orange and white spots become bigger. Their little feet, called prolegs, become thick and pudgy like little marshmallows.

Just molted 5th instar anise swallowtail caterpillar. Note the bright green with black stripes and yellow spots

Fifth Instar

Fully grown caterpillars reach about 2 inches in length and are bright green with a black and orange/yellow stripe pattern. Their body is smooth and the spikey setae have shed with their skin.


Your chubby caterpillar will have a huge wet poop. Seeing this indicates that the caterpillar will begin to search for a branch for its final metamorphosis. Once the caterpillar decides on a perfect spot, it will use strong silk to attach itself to the branch with its head facing up (unlike the monarch butterfly that hangs upside down). It slowly bends into a hook shape and releases all its feet until it’s only hanging from two silk threads. This can happen quickly or take place gradually over a day or two. If you notice your caterpillar has stopped moving, don’t worry, something magical is happening!

Getting ready to turn into a chrysalis!
Just molted into a chrysalis
Chrysalis turns brown to match the branch

Butterfly caterpillars DO NOT SPIN COCOONS!

The chrysalis is the pupa stage where the metamorphosis takes place. The anise caterpillar molts one last time shedding its skin to reveal a pale green chrysalis. This is pure magic if you are lucky enough to witness the process as it happens. The chrysalis gradually turns a grayish-brown pattern that perfectly camouflages with the dry branch it is attached to. This molting process to chrysalis lasts about 10 minutes.

► Watch a reel of our caterpillar transforming into a chrysalis

A newly emerged butterfly hanging upside down to dry out its wings


The star anise butterflies are unpredictable and can emerge from their chrysalis anywhere from 2 weeks to several months (and even up to 2 years according to Montana Fieldguide). During the heatwave, all our butterflies emerged in less than two weeks! Last year our pupa overwintered and didn’t emerge until spring.

Most of our butterflies emerged late in the afternoon. It takes a couple of hours for their wings to unfurl and dry completely. We brought them outside and waited for them to flutter away. It’s recommended to release them before dark so they have time to find food and shelter.

► Watch a reel of our butterfly that just emerged from its chrysalis

How to care for an anise swallowtail caterpillar

How to keep caterpillar food fresh

Repurpose a drink cup with a lid. Put the plant stems through the straw hole. This keeps the water from evaporating and also prevents the caterpillars and their poop from falling into the water. Caterpillars can drown! Change the water every few days or when it looks cloudy.

► Watch a reel of a caterpillar eating

Caterpillar Habitat from Egg to 4th Instar

Placed the cup holding your caterpillar and its food in a big plastic wash basin to catch all the poop. From the egg stage to the 4th instar phase, this is the only habitat your caterpillar needs. You may need to replace the plants if they wilt and die. Just cut a new sprig into fresh water. Dump out the poop when you feel it’s time. It is quite astonishing how much poop a tiny creature can produce. Consider it free fertilizer for your garden!

► Watch a reel of a caterpillar pooping

For the majority of the caterpillar’s life, you can keep it out in the open for better observation. Some caterpillar behaviors to observe are their eating habits, witnessing them shed their old skin and grow larger with each molt, observing them eat their discarded skin, and even the fascinating act of caterpillar pooping. If you’re lucky, you may even witness the final molt when it transforms into a chrysalis and slowly watch it change from green to brown to blend in with tree bark.

Enclosed Habitat during the 5th Instar Stage

It’s hard to keep track of the molts but you will know your caterpillar is in its 5th instar stage when it turns bright green. You will need to put the caterpillar into an enclosed habitat. A 5th instar caterpillar will consume a lot of food and then begin wandering to look for a spot to pupate. It can travel quite far in your home. During our first caterpillar experience, we found a caterpillar that had traveled about 200 feet and was hiding between the folds of our curtain! Thankfully I was able to move it back to the butterfly habitat so it could attach to a branch instead.

Mesh caterpillar habitat

The first year we raised caterpillars, we got a couple of these round pop-up butterfly habitats. They worked just fine but visibility is limited to the top of the enclosure. I saw a rectangular butterfly habitat that has a big clear window on one side that is better for observation.

The second year we raised caterpillars, I created an enclosure out of an old comforter bag. We could unzip it to get a clearer view of the caterpillar or to clean the poop. A large bucket, plastic container, reptile tank, or old aquarium can also be a nice enclosure for your caterpillar. Place the cup with the caterpillar and food into the container along with some dry branches. I read that you don’t need the branches but I think it will feel more natural for the caterpillar and the chrysalis is meant to camouflage with a dry branch.

Make sure there is enough airflow. Keep the habitat away from direct sunlight and heat.

Do not disturb!

Be careful not to handle or touch the caterpillars, even if they are not moving and you are worried. They attach themselves to the branch and slowly climb out of their skin. If the caterpillar is detached in the process of molting it will die because it cannot pull itself out of the old skin.

Provoked caterpillar displaying stinkhorns, image credit:

Caterpillar Stinkhorns!

When startled, orange feather-like antennae pop out of the caterpillar’s head and emit a terrible smell. They are not actually antennae, but rather protruding glands called osmeterium also known as stinkhorns. The osmeterium can be observed from the second instar stage.

Fun facts about Caterpillars and butterflies

  • Caterpillars are insects, not worms.
  • Both butterflies and moths start life as a caterpillar. Butterflies molt into chrysalises while moths spin cocoons.
  • Caterpillars poop a lot, but butterflies do not poop or pee!
  • Swallowtail caterpillars have an organ on the top of their heads that look like orange horns. These are called osmeterium. When startled, swallowtail caterpillars stick out their osmeterium and emit a foul smell.
  • Swallowtail butterflies lay one egg at a time and can lay about 50 eggs each day

In many cultures, butterflies represent love, long life, and good fortune. For Indigenous tribes in Taiwan, the butterfly is a symbol of swiftness. Each year in Taiwan, the annual Yellow Butterfly Festival promotes the preservation of Taiwan’s ecology and natural resources.

Picture books about caterpillars and butterflies


English Title: The Very Impatient Caterpillar
Language: Traditional Chinese, Zhuyin

This is a very funny story about a caterpillar that can’t wait to become a butterfly. He has many questions and concerns as he impatiently awaits his transformation.

Buy from Yo! Baby

Kai the Dancing Butterfly

Readers are treated to a delightful exploration of Taiwan’s breathtaking natural landscapes, its diverse and fascinating animal species, and the rich tapestry of Indigenous cultures that make the island so unique. This enchanting children’s book is a must-read for those who already love Taiwan or anyone eager to delve into the wonders of Taiwanese culture.

This is an English language book with some Traditional Chinese vocabulary about Taiwan

Order from Amazon

Anise Butterfly Vocabulary in English and Chinese

Below are several vocabulary terms associated with butterflies and caterpillars. I also include simple phrases to help jumpstart conversations with your child.


A butterfly is a flying insect with 4 wings that are usually very colorful. There are two wings on each side that are attached to a long thin body.

Traditional Chinese: 蝴蝶
Mandarin Pinyin: húdié
Phrase in Mandarin: 蝴蝶有一個長長的舌頭
(Butterflies have very long tongues)

Swallowtail Butterfly

You can identify a swallowtail butterfly by the characteristic tail on the small lower wings

Traditional Chinese: 鳳蝶
Mandarin Pinyin: fèng dié
Phrase in Mandarin: 鳳蝶的翅膀好特別
(A swallowtail butterfly’s wings are so unique)

Butterfly Life Cycle

A butterfly’s life cycle is defined as all the four developmental stages it goes through from egg, larvae, pupa, and adult.

Traditional Chinese: 蝴蝶生命週期
Mandarin Pinyin: húdié shēngmìng zhōuqí
Phrase in Mandarin: 蝴蝶的生命週期有 4 個階段
(a butterfly’s lifecycle has 4 stages)

Butterfly Egg

Traditional Chinese: 卵
Mandarin Pinyin: luǎn
Phrase in Mandarin: 蝴蝶的蛋是叫卵
(Butterfly eggs are called 卵 in Mandarin Chinese)


Larva of butterflies and moths are called caterpillars and is the second stage of the insect’s life cycle.

Traditional Chinese: 毛毛蟲
Mandarin Pinyin: máo máo chóng
Phrase in Mandarin: 肥滋滋的毛毛蟲愛吃植物
(The chubby caterpillar likes to eat plants)

Caterpillar Setae

Setae are the spikes or hairs on a caterpillar’s body. These are sometimes connected to toxic glands and can cause a reaction on the skin. Non-poisonous setae can cause irritation if they get into the eyes. Anise swallowtail caterpillars are not poisonous.

Traditional Chinese: 剛毛
Mandarin Pinyin: gāngmáo
Phrase in Mandarin: 小心不要碰到毛毛蟲身上的剛毛
(Be careful not to touch the setae on the caterpillar)


The osmeterium is an organ that a swallowtail caterpillar protrudes from its head with a stinky odor meant to scare off predators.

Traditional Chinese: 臭角
Mandarin Pinyin: chòu jiǎo
Phrase in Mandarin: 你有看到毛毛蟲橘色的臭角嗎?
(Did you see the caterpillar’s orange osmeterium?)


In order to grow, a caterpillar must shed its skin. This process is called molting

Traditional Chinese: 蛻皮
Mandarin Pinyin: tuìpí
Phrase in Mandarin: 毛毛蟲蛻皮後變更大了
(the caterpillar has become bigger after molting)


A chrysalis is the outer covering that protects the caterpillar as it goes through the metamorphosis to become a butterfly.

Traditional Chinese:
Mandarin Pinyin: yǒng
Phrase in Mandarin: 毛毛蟲已經蛻變成蛹
(The caterpillar has molted into a chrysalis)


The transformation of a caterpillar to pupa to a butterfly is called metamorphosis.

Traditional Chinese: 羽化
Mandarin Pinyin: yǔhuà
Phrase in Mandarin: 毛毛蟲經過羽化之後會變成美麗的蝴蝶
(When metamorphosis is complete, the caterpillar becomes a beautiful butterfly)

Educational worksheets and journey (coming soon)

Apologies for not finishing the worksheets but I wanted to share the post before summer so that you won’t miss out on caterpillar season! Will share them on social media when the worksheets are available for download.

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